Augmented glenoid components and devices for implanting the same

ABSTRACT

A glenoid component for coupling to a scapula of a subject includes a body. The body includes an articulation surface adapted to articulate with a humeral component, and the body further includes a distal surface adapted to face the glenoid of the scapula. The distal surface includes a base surface portion adapted to face a first portion of the glenoid. The distal surface further includes an augmented surface portion adapted to face a second portion of the glenoid. The base surface portion and the augmented surface portion define an obtuse angle therebetween.

TECHNICAL FIELD

The present invention relates to glenoid implants and devices thatfacilitate implanting the same. In particular, the present inventionrelates to implants for glenoids having non-uniform erosion and devicesthat facilitate implanting the same.

BACKGROUND

In a healthy shoulder joint, the head of the humerus interacts with theglenoid of the scapula to form a “ball and socket” joint. The humeralhead abuts and articulates with the glenoid to provide a wide range ofmotion. In an unhealthy shoulder joint, the interaction between theglenoid and the humerus is compromised, requiring repair or replacement.

In some unhealthy shoulder joints, different portions of the glenoid canexperience different amounts of bone erosion. For example and referringto FIGS. 1-4, a glenoid 10 may include a posterior portion 12 that has asignificant amount of erosion and an anterior portion 14 that has littleor no erosion. Such a glenoid is commonly referred to as a “type-B2”glenoid. As another example, a glenoid may include a supero-posteriorportion that has a significant amount of erosion and an infero-anteriorportion that has little or no erosion. As yet another example, a glenoidmay include an infero-posterior portion that has a significant amount oferosion and a supero-anterior portion that has little or no erosion. Inany of these cases, a surgeon may need to remove a significant amount ofbone, specifically, cortical bone of the relatively healthy portions ofthe glenoid, to accommodate typical glenoid implants.

Previously, glenoid components were developed that were specificallyintended to be used with type-B2 glenoids and address the issues oftypical glenoid components described above. Some of these glenoidcomponents, for example, include a scapula-facing surface in whichdifferent portions of the surface are disposed at different“elevations”. These components also include a transversely-extendingsurface that connects the different portions of the scapula-facingsurface. These surfaces provide the glenoid component with a “stepped”appearance. However, these glenoid components nevertheless require asignificant amount of bone removal and typically violate the subchondralplate. In addition, it is relatively difficult to remove bone to form anappropriately shaped surface for receiving a step-shaped glenoidcomponent, and a surgeon must frequently insert a trial implant to checkthe fit with the surface.

FIGS. 5A-5C illustrate a glenoid 10 at different stages of traditionalon-axis reaming. FIG. 5A illustrates a glenoid 10 with a portion of bone11 that has deteriorated from the posterior portion 12. FIG. 5Billustrates a reamer 15 approaching the glenoid 10 along a longitudinalaxis L of the glenoid 10. Portion 13 indicates the portion of bone to beremoved using the reamer 15. As shown in FIG. 5C, following on-axisreaming, a significant portion 13 of the glenoid 10 has beenunnecessarily removed from both the posterior portion 12 and theanterior portion 14.

As another example, FIGS. 6A-6C illustrate a glenoid 10 followingoff-axis reaming at different angles. Traditionally, to accomplishoff-axis reaming, the entire reamer 15 is introduced into the body at anangle (i.e., 8 degrees, 12 degrees, or 18 degrees) relative to thelongitudinal axis L of the bone. However, as shown in FIGS. 6A-6C, agreater portion of the anterior portion 14 is still unnecessarilyremoved from the glenoid 10 than is necessary for the implantation ofglenoid components created for type-B2 glenoids.

FIGS. 7A and 7B illustrate yet another glenoid 10 following preparationof the bone for the insertion of a GLOBAL® STEPTECH® Anchor Peg Glenoid.In this method, a significant portion of the posterior portion 12 of theglenoid 10 has been unnecessarily removed in a stepped manner.Accordingly, there is a need for a device that minimizes the amount ofbone removed.

Others of these glenoid components, for example, include ascapula-facing surface that has a constant slope. However, forces actingon the proximal or articulation surface of these components urge thesloped scapula-facing surface to slide over the prepared glenoid. Thisaction, in turn, applies shear forces to posts or anchors that extendfrom the scapula-facing surface and couple to the bone. These glenoidcomponents also present challenges to surgeons. Specifically, thereaming path for preparing the glenoid is typically across the glenoid.

SUMMARY

In some embodiments, a glenoid component for coupling to a scapula of asubject includes a body. The body includes an articulation surfaceadapted to articulate with a humeral component, and the body furtherincludes a distal surface adapted to face the glenoid of the scapula.The distal surface includes a base surface portion including a firstconvex surface adapted to face a first portion of the glenoid. Thedistal surface further includes an augmented surface portion including asecond convex surface adapted to face a second portion of the glenoid.The base surface portion and the augmented surface portion are connectedtherebetween by an interface. The first convex surface may include afirst radius of curvature and the second convex surface may include asecond radius of curvature. In particular embodiments, the first andsecond radius of curvature may be the same. The first convex surface mayextend from the interface to an anterior portion of the glenoid implant.The second convex surface may extend from the interface to at least oneof a posterior portion, supero-posterior portion or an infero-posteriorportion of the implant.

In some embodiments, a device for removing bone from a glenoid of asubject includes a frame that is adapted to be manipulated by a user. Adrive shaft is rotatably supported by the frame and adapted to berotatably driven about a drive axis. A reaming head includes at leastone reaming edge adapted to engage the glenoid of the subject. Thereaming head is adapted to be rotatably driven about a reaming axis bythe drive shaft, and the reaming axis is non-parallel to the drive axis.

In some embodiments, a device for removing bone from a glenoid of asubject includes a frame adapted to be manipulated by a user and areaming head including a reaming surface. A drive shaft is rotatablysupported by and extends through the frame and has a distal end coupledwith the reaming head. The drive shaft is adapted to be rotatably drivenabout a drive shaft axis. A guard member is coupled to a distal portionof the frame. The guard member is configured to inhibit a portion of thereaming surface from engaging bone.

In some embodiments, a device for removing bone from a glenoid of asubject includes a frame adapted to be manipulated by a user and areaming head including a reaming surface. A cannulated drive shaft isrotatably supported by and extends at least partially through the frameand has a distal end coupled with the reaming head. The drive shaft isadapted to be rotatably driven about a drive shaft axis. The device hasa first configuration to rotate the reaming head about a first reamingaxis when the reaming head is in a first orientation. The device has asecond configuration to rotate the reaming head about a second reamingaxis when the reaming head is in a second orientation.

While multiple embodiments are disclosed, still other embodiments of thepresent invention will become apparent to those skilled in the art fromthe following detailed description, which shows and describesillustrative embodiments of the invention. Accordingly, the drawings anddetailed description are to be regarded as illustrative in nature andnot restrictive.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1-4 are illustrations of type-B2 glenoids.

FIGS. 5A-5C illustrate a glenoid at different stages of a traditionalmethod of on-axis reaming.

FIGS. 6A-6C illustrate glenoids following traditional off-axis reamingat different angles.

FIGS. 7A and 7B illustrate a glenoid at different stages of a method ofreaming in preparation for the GLOBAL® STEPTECH® Anchor Peg Glenoid.

FIG. 8 is a perspective view of a glenoid component according toembodiments of the present invention.

FIG. 9 is another perspective view of the glenoid component of FIG. 8.

FIG. 10 is another perspective view of the glenoid component of FIG. 8.

FIG. 11 is another perspective view of the glenoid component of FIG. 8.

FIG. 12 is a top view of the glenoid component of FIG. 8.

FIG. 13 is a side view of the glenoid component of FIG. 8.

FIG. 14 is a front view of the glenoid component of FIG. 8.

FIG. 15 is a perspective sectional view of the glenoid component alongline 15-15 of FIG. 14.

FIG. 16 is a bottom sectional view of the glenoid component along line16-16 of FIG. 14.

FIG. 17 is a top sectional view of the glenoid component along line15-15 of FIG. 14.

FIG. 18 is a perspective view of a glenoid component according toembodiments of the present invention.

FIG. 19 is another perspective view of the glenoid component of FIG. 18.

FIG. 20 is another perspective view of the glenoid component of FIG. 18.

FIG. 21 is a perspective section view of the glenoid component alongline 21-21 of FIG. 18.

FIG. 22 is a perspective sectional view of the glenoid component alongline 22-22 of FIG. 18.

FIG. 23 is a perspective sectional view of the glenoid component alongline 23-23 of FIG. 18.

FIG. 24 is a perspective sectional view of the glenoid component alongline 24-24 of FIG. 18.

FIG. 25 is a perspective view of a glenoid component according toembodiments of the present invention.

FIG. 26 is another perspective view of the glenoid component of FIG. 25.

FIG. 27 is another perspective view of the glenoid component of FIG. 25.

FIG. 28 is a perspective section view of the glenoid component alongline 28-28 of FIG. 25.

FIG. 29 is another perspective sectional view of the glenoid componentalong line 28-28 of FIG. 25.

FIG. 30 is a perspective sectional view of the glenoid component alongline 30-30 of FIG. 25.

FIG. 31 is a perspective sectional view of the glenoid component alongline 31-31 of FIG. 25.

FIG. 32 is a front view of a reaming device according to embodiments ofthe present invention.

FIG. 33 is a rear longitudinal sectional view of the reaming device ofFIG. 32.

FIG. 34 is a detail front view of a proximal end of the reaming deviceof FIG. 32.

FIG. 35 is a detail rear longitudinal sectional view of the proximal endof the reaming device of FIG. 32.

FIG. 36 is a detail rear longitudinal sectional view of an intermediatesection of the reaming device of FIG. 32.

FIG. 37 is a detail front view of a distal end of the reaming device ofFIG. 32.

FIG. 38 is a detail rear longitudinal sectional view of the distal endof the reaming device of FIG. 32. A reaming head of the reaming deviceis shown in a first orientation.

FIG. 39 is a detail rear longitudinal sectional view of the distal endof the reaming device of FIG. 32. The reaming head is shown in a secondorientation.

FIG. 40 illustrates a perspective view of another embodiment of areaming device.

FIG. 41 illustrates another perspective view of the reaming device shownin FIG. 40.

FIG. 42 illustrates a partial-exploded view of the reaming device shownin FIG. 40.

FIG. 43 illustrates a cross-section of the reaming device shown in FIG.40 taken through line 43-43.

FIG. 44 illustrates a bottom view of the reaming device shown in FIG.40.

FIG. 45 is a front view of a reaming device according to embodiments ofthe present invention.

FIG. 46 is a flowchart of an exemplary method for coupling a glenoidcomponent to a scapula of a subject according to embodiments of thepresent invention.

FIG. 47 illustrates forming a first concave surface in a scapula of asubject.

FIGS. 48 and 49 illustrate forming a second concave surface in a scapulaof a subject.

FIGS. 50 and 51 illustrate connecting a glenoid component to the scapulaof a subject.

While the invention is amenable to various modifications and alternativeforms, specific embodiments have been shown by way of example in thedrawings and are described in detail below. The intention, however, isnot to limit the invention to the particular embodiments described. Onthe contrary, the invention is intended to cover all modifications,equivalents, and alternatives falling within the scope of the inventionas defined by the appended claims.

DETAILED DESCRIPTION

FIGS. 8-17 illustrate an exemplary glenoid component or implant 100according to embodiments of the present invention. The glenoid component100 is adapted to be positioned between the scapula of a subject (notshown) and a humeral component. The glenoid component 100 is alsoadapted to articulate with the humeral component. The humeral componentmay be a humeral prosthesis secured to the humerus of the subject or ananatomical humeral head of the subject (see, for example, the humeralhead 16 shown in FIG. 1).

The glenoid component 100 includes a body 104 having a proximal orarticulation surface 106. The articulation surface 106 is concave andadapted to engage the humeral component. The articulation surface 106receives at least a portion of the humeral component within theconcavity defined by the articulation surface 106.

Opposite the articulation surface 106, the body 104 includes a distal orscapula-facing surface 108. In some embodiments, the distal surface 108supports one or more securing and/or stabilizing anchors, pins, or posts110 (referred to herein as anchors). The anchors 110 may be received inpre-drilled holes in the scapula (not shown). The anchors 110 may havegenerally cylindrical shapes, and the ends opposite the body 104 of theglenoid component 100 may be conical or frusto-conical to facilitateinsertion into the pre-drilled holes formed in the scapula. The anchors110 may have various lengths and/or different lengths relative to eachother.

The anchors 110 may have features that facilitate securement to thescapula. For example, one or more of the anchors 110 may include one ormore radially-outwardly extending fins 112. As another example, one ormore of the anchors 110 may include one or more transversely extendinggrooves 114.

The anchors 110 may be arranged on the distal surface 108 in variousmanners. For example and as shown in the figures, one anchor 110 may becentrally positioned, one anchor 110 may be superiorly positioned, andtwo anchors 110 may be inferiorly positioned.

In some embodiments, the anchors 110 may be arranged and configured inany of the manners described in U.S. Patent App. Pub. 2010/0228352,published on Sep. 9, 2010, which is hereby incorporated by reference inits entirety. In other embodiments one or more anchors may include akeel, finned keel, or other structures. See for example U.S. Patent App.Pub. 2013/0144393, published on Jun. 6, 2013, which is herebyincorporated by reference in its entirety.

The distal surface 108 of the glenoid component 100 is adapted to facethe glenoid of the subject. In some embodiments, the glenoid may be ananatomical type-B2 glenoid (see, for example, the glenoid 10 shown inFIG. 1) or a type-B2 glenoid that is at least partially prepared forreceiving the glenoid component 100 (for example, by removing bone fromthe glenoid).

The distal surface 108 of the glenoid component 100 includes differentportions that face different portions of the glenoid. The differentportions of the glenoid may have experienced different amounts of boneerosion. Specifically, the distal surface 108 includes a base surfaceportion 116 that is adapted to face a first portion of the glenoid. Insome embodiments, the first portion is a relatively healthy (that is,having little or no bone erosion) anterior portion of the glenoid. Theanterior portion of the glenoid may be an anatomical surface or asurface that is at least partially prepared for receiving the glenoidcomponent 100. The distal surface 108 also includes an augmented surfaceportion 118 that is adapted to face a second portion of the glenoid. Insome embodiments, the second portion is a relatively unhealthy (that is,having a significant amount of bone erosion) posterior portion of theglenoid. The posterior portion of the glenoid may be an anatomicalsurface or a surface that is at least partially prepared for receivingthe glenoid component 100.

As shown most clearly in FIGS. 15-17, the augmented surface portion 118is generally disposed further from the articulation surface 106 than thebase surface portion 116. Stated another way, the body 104 of theglenoid component 100 is relatively thin between base surface portion116 and the articulation surface 106. In contrast, the body 104 of theglenoid component 100 is relatively thick between the augmented surfaceportion 118 and the articulation surface 106.

In some embodiments, the base surface portion 116 is a convex surface.The base surface portion 116 may have a curved shape (for example, anarcuate shape) in a transverse plane 120 that extends through thearticulation surface 106, the base surface portion 116, and theaugmented surface portion 118 (that is, a plane extending through thebody 104 in a thickness direction and substantially bisecting each ofthe surfaces 106, 116, and 118; see FIG. 9). The base surface portion116 may have a curved shape (for example, an arcuate shape) in alongitudinal plane 122 that extends through the articulation surface 106and the base surface portion 116 and is disposed apart from theaugmented surface portion 118 (that is, a plane extending through thebody 104 in a thickness direction, substantially perpendicular to thetransverse plane 120, substantially bisecting the base surface portion116, and not intersecting with the augmented surface portion 118; seeFIG. 9).

In some embodiments, the augmented surface portion 118 is a convexsurface. The augmented surface portion 118 may have a curved shape (forexample, an arcuate shape) in the transverse plane 120 (see FIG. 11).The augmented surface portion 118 may have a curved shape (for example,an arcuate shape) in a longitudinal plane 124 that extends through thearticulation surface 106 and the augmented surface portion 118 and isdisposed apart from the base surface portion 116 (that is, a planeextending through the body 104 in a thickness direction, substantiallyparallel to the longitudinal plane 122, substantially bisecting theaugmented surface portion 118, and not intersecting with the basesurface portion 116; see FIG. 11).

The augmented surface portion 118 and the base surface portion 116intersect at an interface 126. In other words, the base surface portion116 and the augmented surface portion 118 are connected by or intersectat the interface 126. In some embodiments, the augmented surface portion118 and the base surface portion 116 define an obtuse angle 128 at theinterface 126 (see FIG. 8). More specifically, the base surface portion116 has a first convex surface 116 a, extending from the interface 126to an anterior portion of the implant and adapted to face a firstportion of the glenoid. The augmented surface portion 118 has a secondconvex surface 118 a, extending from the interface to at least one of aposterior portion, a supero-posterior portion, or an infero portion ofthe glenoid implant and adapted to face a second portion of the glenoid.Stated another way, the base surface portion 116 has a first,relatively-gradual slope toward the interface 126 and the augmentedsurface portion 118 has a second, relatively-inclined slope toward theinterface 126. The first convex surface 116 a has a first radius ofcurvature and the second convex surface 118 a has a second radius ofcurvature. The first radius of curvature and the second radius ofcurvature may be the same or different. In some embodiments, theinterface 126 substantially extends in a direction parallel to thelongitudinal planes 122 and 124 (see FIG. 14). That is, the interface126 may curve slightly relative to the planes 122 and 124 due to theshapes of the augmented surface portion 118 and the base surface portion116.

FIGS. 18-24 illustrate an exemplary glenoid component or implant 200according to embodiments of the present invention. The glenoid component200 is adapted to be positioned between the scapula of a subject and ahumeral component. The glenoid component 200 is also adapted toarticulate with the humeral component. The humeral component may be ahumeral prosthesis secured to the humerus of the subject or ananatomical humeral head of the subject (see, for example, the humeralhead 16 shown in FIG. 1).

The glenoid component 200 includes a body 204 having a proximal orarticulation surface 206. The articulation surface 206 is concave andadapted to engage the humeral component. The articulation surface 206receives at least a portion of the humeral component within theconcavity defined by the articulation surface 206.

Opposite the articulation surface 206, the body 204 includes a distal orscapula-facing surface 208. In some embodiments, the distal surface 208supports one or more securing and/or stabilizing anchors, pins, or posts210 which may have the same features and/or be arranged in the samemanner as the anchors 110 described above.

The distal surface 208 of the glenoid component 200 is adapted to facethe glenoid of the subject. In some embodiments, the glenoid may be ananatomical glenoid that has significant supero-posterior erosion andlittle or no infero-anterior erosion or such a glenoid that is at leastpartially prepared for receiving the glenoid component 200 (for example,by removing bone from the glenoid).

The distal surface 208 of the glenoid component 200 includes differentportions that face different portions of the glenoid. Specifically, thedistal surface 208 includes a base surface portion 216 that is adaptedto face the infero-anterior portion of the glenoid. The distal surface208 also includes an augmented surface portion 218 that is adapted toface the supero-posterior portion of the glenoid.

As shown most clearly in FIGS. 21-24, the augmented surface portion 218is generally disposed further from the articulation surface 206 than thebase surface portion 216. Stated another way, the body 204 of theglenoid component 200 is relatively thin between base surface portion216 and the articulation surface 206. In contrast, the body 204 of theglenoid component 200 is relatively thick between the augmented surfaceportion 218 and the articulation surface 206.

In some embodiments, the base surface portion 216 is a convex surface.The base surface portion 216 may have a curved shape (for example, anarcuate shape) in a plane 220 that extends through the articulationsurface 206, the base surface portion 216, and the augmented surfaceportion 218 (that is, a plane extending through the body 204 in athickness direction and substantially bisecting each of the surfaces206, 216, and 218; see FIG. 19). The base surface portion 216 may have acurved shape (for example, an arcuate shape) in a plane 222 that extendsthrough the articulation surface 206 and the base surface portion 216and is disposed apart from the augmented surface portion 218 (that is, aplane extending through the body 204 in a thickness direction,substantially bisecting the base surface portion 216, and notintersecting with the augmented surface portion 218; see FIG. 20).

In some embodiments, the augmented surface portion 218 is a convexsurface. The augmented surface portion 218 may have a curved shape (forexample, an arcuate shape) in the plane 220 (see FIG. 23). The augmentedsurface portion 218 may have a curved shape (for example, an arcuateshape) in a longitudinal plane 224 that extends through the articulationsurface 206 and the augmented surface portion 218 and is disposed apartfrom the base surface portion 216 (that is, a plane extending throughthe body 204 in a thickness direction, substantially bisecting theaugmented surface portion 218, and not intersecting with the basesurface portion 216; see FIG. 20).

The augmented surface portion 218 and the base surface portion 216intersect at an interface 226. In other words, the base surface portion216 and the augmented surface portion 218 are connected by or intersectat interface 226. In some embodiments, the augmented surface portion 218and the base surface portion 216 define an obtuse angle 228 at theinterface 226 (see FIG. 19). More specifically, the base surface portion216 has a first convex surface 216 a, extending from the interface 226to an anterior portion of the implant and adapted to face a firstportion of the glenoid. The augmented surface portion 218 has a secondconvex surface 218 a, extending from the interface 226 to at least oneof a posterior portion, a supero-posterior portion, or an infero portionof the glenoid implant and adapted to face a second portion of theglenoid. Stated another way, the base surface portion 216 has a first,relatively-gradual slope toward the interface 226 and the augmentedsurface portion 218 has a second, relatively-inclined slope toward theinterface 226. The first convex surface 216 a has a first radius ofcurvature and the second convex surface 218 a has a second radius ofcurvature. The first radius of curvature and the second radius ofcurvature may be the same or different. In some embodiments, theinterface 226 substantially extends in a direction parallel to theplanes 222 and 224 (see FIG. 20). That is, the interface 226 may curveslightly relative to the planes 222 and 224 due to the shapes of theaugmented surface portion 218 and the base surface portion 216.

FIGS. 25-31 illustrate an exemplary glenoid component or implant 300according to embodiments of the present invention. The glenoid component300 is adapted to be positioned between the scapula of a subject and ahumeral component. The glenoid component 300 is also adapted toarticulate with the humeral component. The humeral component may be ahumeral prosthesis secured to the humerus of the subject or ananatomical humeral head of the subject (see, for example, the humeralhead 16 shown in FIG. 1).

The glenoid component 300 includes a body 304 having a proximal orarticulation surface 306. The articulation surface 306 is concave andadapted to engage the humeral component. The articulation surface 306receives at least a portion of the humeral component within theconcavity defined by the articulation surface 306.

Opposite the articulation surface 306, the body 304 includes a distal orscapula-facing surface 308. In some embodiments, the distal surface 308supports one or more securing and/or stabilizing anchors, pins, or posts310 which may have the same features and/or be arranged in the samemanner as the anchors 110 described above.

The distal surface 308 of the glenoid component 300 is adapted to facethe glenoid of the subject. In some embodiments, the glenoid may be ananatomical glenoid that has significant infero-posterior erosion andlittle or no supero-anterior erosion or such a glenoid that is at leastpartially prepared for receiving the glenoid component 300 (for example,by removing bone from the glenoid).

The distal surface 308 of the glenoid component 300 includes differentportions that face different portions of the glenoid. Specifically, thedistal surface 308 includes a base surface portion 316 that is adaptedto face the supero-anterior portion of the glenoid. The distal surface308 also includes an augmented surface portion 318 that is adapted toface the infero-posterior portion of the glenoid.

As shown most clearly in FIGS. 28-31, the augmented surface portion 318is generally disposed further from the articulation surface 306 than thebase surface portion 316. Stated another way, the body 304 of theglenoid component 300 is relatively thin between base surface portion316 and the articulation surface 306. In contrast, the body 304 of theglenoid component 300 is relatively thick between the augmented surfaceportion 318 and the articulation surface 306.

In some embodiments, the base surface portion 316 is a convex surface.The base surface portion 316 may have a curved shape (for example, anarcuate shape) in a plane 320 that extends through the articulationsurface 306, the base surface portion 316, and the augmented surfaceportion 318 (that is, a plane extending through the body 304 in athickness direction and substantially bisecting each of the surfaces306, 316, and 318; see FIG. 27). The base surface portion 316 may have acurved shape (for example, an arcuate shape) in a plane 322 that extendsthrough the articulation surface 306 and the base surface portion 316and is disposed apart from the augmented surface portion 318 (that is, aplane extending through the body 304 in a thickness direction,substantially bisecting the base surface portion 316, and notintersecting with the augmented surface portion 318; see FIG. 25).

In some embodiments, the augmented surface portion 318 is a convexsurface. The augmented surface portion 318 may have a curved shape (forexample, an arcuate shape) in the plane 320 (see FIG. 26). The augmentedsurface portion 318 may have a curved shape (for example, an arcuateshape) in a longitudinal plane 324 that extends through the articulationsurface 306 and the augmented surface portion 318 and is disposed apartfrom the base surface portion 316 (that is, a plane extending throughthe body 304 in a thickness direction, substantially bisecting theaugmented surface portion 318, and not intersecting with the basesurface portion 316; see FIG. 25).

The augmented surface portion 318 and the base surface portion 316intersect at an interface 326. In other words, the base surface portion316 and the augmented surface portion 318 are connected by the interface326. In some embodiments, the augmented surface portion 318 and the basesurface portion 216 define an obtuse angle 328 at the interface 326 (seeFIG. 19). More specifically, the base surface portion 316 has a firstconvex surface 316 a, extending from the interface 326 to an anteriorportion of the implant and adapted to face a first portion of theglenoid. The augmented surface portion 318 has a second convex surface318 a, extending from the interface 326 to at least one of a posteriorportion, a supero-posterior portion, or an infero portion of the glenoidimplant and adapted to face a second portion of the glenoid. Statedanother way, the base surface portion 316 has a first,relatively-gradual slope toward the interface 326 and the augmentedsurface portion 318 has a second, relatively-inclined slope toward theinterface 326. The first convex surface 316 a has a first radius ofcurvature and the second convex surface 318 a has a second radius ofcurvature. The first radius of curvature and the second radius ofcurvature may be the same or different. In some embodiments, theinterface 326 substantially extends in a direction parallel to theplanes 322 and 324 (see FIG. 25). That is, the interface3 may curveslightly relative to the planes 322 and 324 due to the shapes of theaugmented surface portion 318 and the base surface portion 316.

FIGS. 32-39 illustrate an exemplary reaming device 400 according toembodiments of the present invention. The reaming device 400 mayprepare, or remove, bone from the glenoid of the subject and facilitatessubsequently implanting a glenoid component, such as one of the glenoidcomponents 100, 200, or 300 described above.

The reaming device 400 includes a housing or frame 402 that may bemanipulated by user (for example, a surgeon) to appropriately positionthe reaming device 400 relative to the glenoid of the subject. The frame402 rotatably supports a drive coupling 404 at a proximal end. The drivecoupling 404 is adapted to detachably couple to a prime mover (such as ahand-held drill or the like). The drive coupling 404 also connects toand rotatably drives a drive shaft 406 that is rotatably supported bythe frame 402. The drive shaft 406 can be straight, such that the driveshaft 406 extends along and rotates about a drive axis 408. The driveshaft 406 transmits rotational motion from the proximal end of thereaming device 400 to an opposite, distal end of the device 400, forexample because the distal end of the drive shaft 406 can be at leastpartially disposed within a reaming head 412. As shown in FIG. 33, thedrive shaft 406 can be cannulated, so the reaming device 400 can bedelivered over a guide pin (e.g., a K-wire). The cannulated drive shaft406 can have a distal opening located adjacent to and/or distal of adistal-most portion of a reaming surface of the reaming head 412. Thedistal opening of the cannulated drive shaft 406 may be distal of anaxis of angulation of the reaming head 412.

At the distal end of the device 400, the frame 402 includes a bearing orbushing 410 that can be adjusted to select the angle of a reaming axis414 of the reaming head 412, such that the reaming axis 414 can beparallel or non-parallel to the drive shaft axis 408 at a distal end ofthe drive shaft 406. The bearing 410 facilitates adjustment of the angleof the reaming head 412, such that when the drive shaft 406 rotates thereaming head 412, the reaming head 412 engages the bone asymmetricallyrelative to an axis extending longitudinally through the distal end ofthe draft shaft 406 to ream the bone asymmetrically relative to theaxis. The reaming axis 414 intersects with and can be disposednon-parallel to the drive axis 408 of the shaft 406, for example withinthe reaming head 412. As such, the reaming head 412 may be referred toas “inclined” or “sloped” relative to the frame 402 in someconfigurations. In some embodiments and as described in further detailbelow, the bearing 410 may be pivotally supported by the remainder ofthe frame 402 about an axis 415 that is substantially perpendicular toboth the reaming axis 414 and the drive axis 408. As a result, an angle416 between the reaming axis 414 and the drive axis 408 may beselectively adjusted between two or more orientations (e.g., twoorientations, three orientations, four orientations, or more). Forexample, the reaming device 400 can have a first configuration to rotatethe reaming head 412 about a first reaming axis when the reaming head412 is in a first orientation and a second configuration to rotate thereaming head 412 about a second reaming axis when the reaming head 412is in a second orientation. For example, the first reaming axis can besubstantially aligned with the drive shaft axis 408, and the secondreaming axis can be at a non-parallel angle relative to the drive shaftaxis 408. As another example, the first reaming axis can be at a firstnon-parallel angle relative to the drive shaft axis (e.g., about 8degrees), and the second reaming axis can be at a second non-parallelangle relative to the drive shaft axis 408 (e.g., about 12 degrees).Unlike traditional approaches to reaming (see, e.g., FIGS. 5A-7B), theability to adjust the angle 416 between the reaming axis 414 and thedrive axis 408 enables the user to avoid removing excess bone, e.g., toonly remove the necessary portions of the bone.

The reaming head 412 includes a base 418 (see FIGS. 37 and 38) thatconnects to the bearing 410. The base 418 also supports one or morereaming elements 420, each of which includes a reaming edge or surface422. When the reaming head 412 rotates, the reaming edges 422 may engageand prepare bone (that is, shape the bone) for subsequently receiving aglenoid component, such as one of the glenoid components 100, 200, or300 described above. In some embodiments, each of the reaming edges 422has an outwardly curved shape (for example, an arcuate shape) such thatthe reaming head 412 forms a concave surface in the bone forsubsequently receiving the glenoid component.

The reaming device 400 may include a guard or guard member 424 removablycoupled to a distal portion of the frame 402. The guard member 424 caninclude a generally C-shaped member such that a distal portion of theguard member 424 is disposed distal to the reaming head 412. The guardmember 424 can be shaped such that a plane extending through the distalportion of the guard member 424 is at an angle relative to the driveaxis 408. As such, the guard 424 inhibits the upper portion of thereaming head 412 from engaging bone during a reaming procedure. Theguard 424 is disposed apart from an opposite lower portion of thereaming head 412 (not shown). As such, the lower portion of the reaminghead 412 engages and prepares bone during a reaming procedure. The guard424 may include an attachment element or feature (for example, athreaded hole 426) that detachably mounts a guide post 428. The guidepost 428 may be used to guide advancement of the reaming device 400during a reaming procedure.

The reaming head 412 is rotatably driven by the drive shaft 406 througha coupling mechanism 430, e.g., a pivot coupling (see FIG. 38). Thecoupling mechanism 430 can be a separate component from the reaming head412 that is disposed laterally between the reaming head 412 and thedistal end of the drive shaft 406. Although, in other embodiments, thecoupling mechanism 430 may be a component of the reaming head 412.

The coupling mechanism 430 facilitates rotation of the drive shaft 406and/or the reaming head 412 about the reaming axis 414. The reaming axis414 may be non-parallel to the drive shaft axis 408. In some embodimentsand as shown in the figures, the coupling mechanism 430 includes agenerally sphere-shaped element 432 at the distal end of the drive shaft406. The sphere-shaped element 432 includes one or more slots 434. Theslots 434 may have arcuate shapes and may generally extend in thedirection of the drive axis 408. Each slot 434 translatably receives apost or pin 436 supported by reaming head 412. The posts 436 and thereaming head 412 are rotatably driven by the drive shaft 406 due toengagement between the sphere-shaped element 432 and the posts 436. Asthe reaming head 412 rotates, the posts 436 move upwardly and downwardlyin the slots 434, once per revolution, due to the non-parallelarrangement of the reaming axis 414 and the drive axis 408.

In some embodiments, the reaming device 400 includes a locking mechanism438 that couples the reaming head 412 to the frame 402. A user may movethe locking mechanism 438 between a locked position and an unlockedposition. In the locked position, the locking mechanism 438 inhibitsadjustment of the angle 416 between the drive axis 408 and the reamingaxis 414. In the unlocked position, the locking mechanism 438 permitsadjustment of the angle between the drive axis 408 and the reaming axis414.

In some embodiments and as shown in the figures, the locking mechanism438 includes a handle 440 that may be manipulated by the user to movebetween the locked position and the unlocked position. Specifically, thehandle 440 may be displaced in a direction that is substantiallyperpendicular to the drive axis 408. The handle 440 connects to a rod442 that is translatably supported by the frame 402. Opposite the handle440, the rod 442 connects to a tooth 444. The tooth 444 is removablyreceived in one of a plurality of notches 446 (see FIG. 37) defined bythe bearing 410. The bearing 410 may include three notches 446, althoughthe bearing 410 may alternatively include different numbers of notches446. In any case, each notch 446 defines an angle, or orientation, atwhich the reaming axis 414, and the reaming head 412, may be disposedrelative to the drive axis 408. The reaming axis 414 and the reaminghead 412 may be disposed, for example, at angles of 15 degrees (seeFIGS. 37 and 38), 25 degrees (not shown), and 35 degrees (see FIG. 39)relative to the drive axis 408.

In the locked position, the tooth 444 is received in one of the notches446 to inhibit adjustment of the angle 416 between the drive axis 408and the reaming axis 414. To move to the unlocked position, the user maypull the handle 440 toward the proximal end of the reaming device 400.In the unlocked position, the tooth 444 is disposed apart from thenotches 446. As such, the user may pivot the bearing 410 about the axis415 to adjust the angle 416 between the drive axis 408 and the reamingaxis 414. After pivoting the bearing 410, the locking mechanism 438 maybe moved to the locked position.

In some embodiments, the locking mechanism 438 includes a biasingelement that biases the locking mechanism 438 toward the lockedposition. The biasing element may be a compression spring 450 (see FIG.36) that is carried within the frame 402. When the handle 440 is pulledto move the locking mechanism 438 to the unlocked position, the spring450 is compressed between the frame 402 and an enlarged diameter section452 of the rod 442. As such, the user may release the handle 440 topermit the spring 450 to return the locking mechanism 438 to the lockedposition. Specifically, the spring 450 displaces the rod 442 to causethe tooth 444 to engage one of the notches 446.

FIGS. 40-44 illustrate an exemplary reaming device 400′ similar to thereaming device 400 discussed above except as described differentlybelow. Accordingly, numerals used to identify features of the reamingdevice 400 include an apostrophe (′) to identify like features of thereaming device 400′. The reaming device 400′ includes a reaming head412′ that rotates about a reaming axis 414′ (see FIG. 43). The reamingaxis 414′ intersects with and is non-parallel to the drive axis 408′ ofa drive shaft 406′ (see FIG. 43). The angle between the reaming axis414′ and the drive axis 408′ may be selectively adjusted to enable theuser to reduce the removal of bone that does not need to be removed,e.g., to only remove the portions of the bone that need to be removed toinsert any of the glenoid components described herein.

FIG. 42 shows that the reaming head 412′ can include a base 418′ thatconnects to the bearing 410′. FIG. 44 shows that the base 418′ has areaming surface 419′ that can remove bone. The reaming surface 419′ caninclude one or more reaming elements 420′, each of which includes areaming edge or surface 422′. Each reaming element 420′ can share anedge with another reaming element 420′. For example, the reaming surface419′ can include a number of adjacent rows of reaming elements 420′.When the reaming head 412′ rotates, the reaming edges 422′ may engageand prepare bone (that is, shape the bone) for subsequently receiving aglenoid component, such as one of the glenoid components 100, 200, or300 described above. In some embodiments, each of the reaming elements420′ can be disposed along an outwardly oriented surface (for example,an arcuate or convex shape) such that the reaming head 412′ forms aconcave surface in the bone for subsequently receiving the glenoidcomponent.

The reaming head 412′ is rotatably driven by the drive shaft 406 througha coupling mechanism 430′, e.g., a pivot coupling (see FIG. 43). Thecoupling mechanism 430′ facilitates rotation of the drive shaft 406′ andthe reaming head 412′ about non-parallel axes (that is, the drive axis408′ and the reaming axis 414′).

FIG. 45 illustrates an exemplary reaming device 500 according toembodiments of the present invention. The reaming device 500 may begenerally similar to the reaming device 400 described above. That is,the reaming device 500 includes a reaming head 512 that rotates about areaming axis 514. The reaming axis 514 intersects with and isnon-parallel to the drive axis 508 of a drive shaft (not shown).However, a bearing 510 that rotatably mounts the reaming head 512 isfixedly connected to a remainder of the device frame 502. For example,the bearing 510 may be monolithically formed (for example, formed fromor as a single piece of material) with the remainder of the frame 502.

FIGS. 46-51 illustrate an exemplary method for coupling a glenoidcomponent, such as one of the glenoid components 100, 200, or 300described above, to a scapula of a subject according to embodiments ofthe present invention. At block 600, one or more anchor-receiving holes700 are formed in the scapula 702 of the subject (see FIG. 47). At block602, a guide pin 704 is inserted into one of the anchor-receiving holes700. At block 604, a first concave surface 706 is formed in the scapula702 of the subject. In some embodiments, the surface 706 may be formedby using a reaming device that has parallel drive and reaming axes(e.g., having a reaming axis in a direction similar to FIGS. 5A-5C). Insome embodiments, the surface 706 may be formed by using the reamingdevice 400 described above. The reaming head 412 may be oriented at arelatively shallow angle (for example, 15 degrees). In some embodiments,the surface 706 may be formed at a portion of the glenoid that hasexperienced little to no erosion, such as an anterior portion, asupero-anterior portion, or an infero-anterior portion.

At block 606, a second concave surface 708 is formed in the scapula 702of the subject (see FIGS. 48 and 49). In some embodiments, the surface708 may be formed by using one of the reaming devices 400 or 500described above. In some embodiments, the reaming head 412 may beoriented at a relatively steep angle (for example, 35 degrees). In someembodiments, the second concave surface 708 may be formed at a portionof the glenoid that has experienced a significant amount of erosion,such as a posterior portion, a supero-posterior portion, or aninfero-posterior portion.

At block 608, the guide pin 704 is removed from the scapula 702. Atblock 610, a glenoid component 710 is connected to the scapula 702 (seeFIGS. 50 and 51). If the glenoid component 710 is, for example, theglenoid component 100 described above, the base surface portion 116 mayface the first concave surface 706 and the augmented surface portion 118may face the second concave surface 708.

The glenoid components, reaming instruments, and methods described abovemay be subjected to various other modifications. For example, in someembodiments the glenoid components described above may have an offsetcenter as described in U.S. Patent App. Pub. 2011/0125273, published onMay 26, 2011, which is hereby incorporated by reference in its entirety.In some embodiments, the center of the glenoid-facing surface is offsetfrom an axis of symmetry of the articulation surface. In someembodiments, the interface between the base surface portion and theaugmented surface portion is offset from the barycentre of thearticulation surface.

Various modifications and additions can be made to the exemplaryembodiments discussed without departing from the scope of the presentinvention. For example, while the embodiments described above refer toparticular features, the scope of this invention also includesembodiments having different combinations of features and embodimentsthat do not include all of the described features. Accordingly, thescope of the present invention is intended to embrace all suchalternatives, modifications, and variations as fall within the scope ofthe claims, together with all equivalents thereof.

As used herein, the relative terms “proximal” and “distal” whendescribing the reaming device shall be defined from the perspective ofthe reaming device. Thus, proximal refers to the direction of the drivecoupling of the reaming device and distal refers to the direction of thereaming head.

Conditional language, such as “can,” “could,” “might,” or “may,” unlessspecifically stated otherwise, or otherwise understood within thecontext as used, is generally intended to convey that certainembodiments include, while other embodiments do not include, certainfeatures, elements, and/or steps. Thus, such conditional language is notgenerally intended to imply that features, elements, and/or steps are inany way required for one or more embodiments.

For purposes of this disclosure, certain aspects, advantages, and novelfeatures are described herein. It is to be understood that notnecessarily all such advantages may be achieved in accordance with anyparticular embodiment. Thus, for example, those skilled in the art willrecognize that the disclosure may be embodied or carried out in a mannerthat achieves one advantage or a group of advantages as taught hereinwithout necessarily achieving other advantages as may be taught orsuggested herein.

Moreover, while illustrative embodiments have been described herein, thescope of any and all embodiments having equivalent elements,modifications, omissions, combinations (e.g., of aspects across variousembodiments), adaptations and/or alterations as would be appreciated bythose in the art based on the present disclosure. The limitations in theclaims are to be interpreted broadly based on the language employed inthe claims and not limited to the examples described in the presentspecification or during the prosecution of the application, whichexamples are to be construed as non-exclusive. Further, the actions ofthe disclosed processes and methods may be modified in any manner,including by reordering actions and/or inserting additional actionsand/or deleting actions. It is intended, therefore, that thespecification and examples be considered as illustrative only, with atrue scope and spirit being indicated by the claims and their full scopeof equivalents.

Any methods disclosed herein need not be performed in the order recited.The methods disclosed herein include certain actions taken by apractitioner; however, they can also include any third-party instructionof those actions, either expressly or by implication. For example,actions such as “forming anchor-receiving holes in scapula” include“instructing formation of anchor-receiving holes in scapula.”

EXAMPLE EMBODIMENTS

The following example embodiments identify some possible permutations ofcombinations of features disclosed herein, although other permutationsof combinations of features are also possible.

1. A glenoid component for coupling to a scapula of a subject, theglenoid component comprising:

-   -   a body including an articulation surface adapted to articulate        with a humeral component, and the body further including a        distal surface adapted to face a glenoid of the scapula, the        distal surface including:    -   a base surface portion including a first convex surface adapted        to face a first portion of the glenoid; and    -   an augmented surface portion including a second convex surface        adapted to face a second portion of the glenoid;    -   wherein the base surface portion and the augmented surface        portion are connected therebetween by an interface.

2. The glenoid component of Embodiment 1, wherein the interface issubstantially planar.

3. The glenoid component of Embodiment 1 or 2, wherein the first convexsurface has a first radius of curvature.

4. The glenoid component of Embodiment 3, wherein the second convexsurface has a second radius of curvature.

5. The glenoid component of Embodiment 4, wherein the first radius ofcurvature is the same as the second radius of curvature.

6. The glenoid component of any one of the preceding Embodiments,wherein the first convex surface extends from the interface to ananterior portion of the glenoid component.

7. The glenoid component of any one of the preceding Embodiments,wherein the second convex surface extends from the interface to at leastone of a posterior portion, a supero-posterior portion or aninfero-posterior portion of the glenoid component.

8. The glenoid component of any one of the preceding Embodiments,wherein the augmented surface portion has a curved shape in a planeextending through the articulation surface, the base surface portion,and the augmented surface portion.

9. The glenoid component of any one of Embodiments 1 to 7, wherein theaugmented surface portion has a curved shape in a plane extendingthrough the articulation surface and the augmented surface portion, andthe plane is disposed apart from the base surface portion.

10. The glenoid component of any one of the preceding Embodiments,further comprising a plurality of anchors extending from the distalsurface and adapted to be received by the scapula.

11. The glenoid component of any one of the preceding Embodiments,wherein the augmented surface portion and the base portion define anobtuse angle at the interface.

12. A device for removing bone from a glenoid of a subject, the devicecomprising:

-   -   a frame adapted to be manipulated by a user;    -   a reaming head comprising a reaming surface;    -   a drive shaft rotatably supported by and extending through the        frame and having a distal end coupled with the reaming head, the        drive shaft rotatable about a drive shaft axis at the distal        end; and    -   a bearing supported by the frame, the bearing capable of        providing a rotational axis of the reaming head that is        non-parallel to the drive shaft axis at the distal end.

13. The device of Embodiment 12, wherein the drive shaft issubstantially straight and has a distal end at least partially disposedwithin the reaming head.

14. The device of Embodiment 12 or 13, further comprising a pivotcoupling disposed laterally between the reaming head and the distal endof the drive shaft.

15. The device of any one of Embodiments 12 to 14, wherein anintersection of the rotational axis of the reamer and the drive shaftaxis is disposed within the reaming head.

16. The device of any one of Embodiments 12 to 15, wherein, inoperation, the device is configured such that when the drive shaftrotates the reaming head, the reaming head engages the boneasymmetrically relative to an axis extending longitudinally through thedistal end of the drive shaft to ream the bone asymmetrically relativeto the axis.

17. A device for removing bone from a glenoid of a subject, the devicecomprising:

-   -   a frame adapted to be manipulated by a user;    -   a reaming head comprising a reaming surface; and    -   a drive shaft rotatably supported by and extending through the        frame and having a distal end coupled with the reaming head, the        drive shaft rotatable about a drive shaft axis; and    -   a guard member coupled to a distal portion of the frame, the        guard member configured to inhibit a portion of the reaming        surface from engaging bone.

18. The device of Embodiment 17, wherein the guard member is generallyC-shaped.

19. The device of Embodiment 17 or 18, wherein a distal portion of theguard member is distal to the reaming head.

20. The device of Embodiment 19, wherein the distal portion of the guardmember is spaced apart from the reaming surface.

21. The device of any one of Embodiments 17 to 20, wherein a distalportion of the guard member is configured to be detachably mounted to aguide post.

22. The device of Embodiment 21, wherein the distal portion of the guardmember comprises an attachment feature configured to be detachablymounted to the guide post.

23. The device of any one of Embodiments 17 to 22, wherein the reamingsurface comprises a plurality of reaming elements configured to shapebone.

24. The device of Embodiment 23, wherein each reaming element shares anedge with another reaming element.

25. The device of Embodiment 23 or 24, wherein each reaming elementcomprises a curved reaming surface.

26. A device for removing bone from a glenoid of a subject, the devicecomprising:

-   -   a frame adapted to be manipulated by a user;    -   a reaming head comprising a reaming surface;    -   a cannulated drive shaft rotatably supported by and extending at        least partially through the frame and having a distal end        coupled with the reaming head, the drive shaft rotatable about a        drive shaft axis; and    -   wherein the device has a first configuration to rotate the        reaming head about a first reaming axis when the reaming head is        in a first orientation; and    -   wherein the device has a second configuration to rotate the        reaming head about a second reaming axis when the reaming head        is in a second orientation.

27. The device of Embodiment 26, wherein the cannulated drive shaft hasa distal opening located adjacent to a distal-most portion of thereaming surface.

28. The device of Embodiment 26 or 27, wherein the cannulated driveshaft has a distal opening located distal of a distal-most portion ofthe reaming surface.

29. The device of any one of Embodiments 26 to 28, wherein thecannulated drive shaft has a distal opening located distal of an axis ofangulation of reaming head.

30. The device of any one of Embodiments 26 to 29, wherein the reamingaxis and the drive shaft axis intersect within the reaming head when anon-zero angle is provided between the reaming axis and the drive shaftaxis.

31. A kit comprising:

-   -   the device of any one of Embodiments 26 to 30; and    -   a guide pin having a first end configured to be disposed in bone        and a second end configured to be received within the cannulated        drive shaft.

What is claimed is:
 1. A device for removing bone from a glenoid of asubject, the device comprising: a frame adapted to be manipulated by auser; a reaming head comprising a reaming surface; a drive shaftrotatably supported by and extending through the frame and having adistal end at least partially disposed within the reaming head, thedrive shaft rotatable about a drive shaft axis at the distal end; and abearing supported by the frame, the bearing capable of providing arotational axis of the reaming head between a minimum angle definedbetween the rotational axis and the drive shaft axis and a maximum angledefined between the rotational axis and the drive shaft axis; whereinthe reaming head is rotated about the rotational axis upon rotation ofthe drive shaft relative to the frame and about the drive shaft axiswhen the device is operated to remove bone from the glenoid; and whereinwhen the bearing provides the maximum angle, a non-zero angle is definedbetween the rotational axis and the drive shaft axis, an intersection ofthe rotational axis and the drive shaft axis is disposed within thereaming head.
 2. The device of claim 1, wherein the drive shaft isstraight when the non-zero angle is defined between the rotational axisand the drive shaft axis.
 3. The device of claim 1, further comprising apivot coupling disposed laterally between the reaming head and thedistal end of the drive shaft.
 4. The device of claim 1, wherein, inoperation, the device is configured such that when the drive shaftrotates the reaming head, the reaming head engages the boneasymmetrically relative to an axis extending longitudinally through thedistal end of the drive shaft to ream the bone asymmetrically relativeto the axis.
 5. The device of claim 1, further comprising: a guardmember having a distal portion and a proximal portion, the proximalportion coupled to a distal portion of the frame, the guard memberconfigured to inhibit a portion of the reaming surface from engagingbone, wherein the guard member extends around a lateral edge of thereaming head so that the distal portion of the guard member is disposeddistal to at least a portion of a distal face of the reaming head, andwherein the distal portion of the guard member is at least partiallypositioned radially inward of the lateral edge of the reaming head. 6.The device of claim 5, wherein the guard member is generally C-shaped.7. The device of claim 5, wherein the distal portion of the guard memberis configured to be detachably mounted to a guide post.
 8. The device ofclaim 7, wherein the distal portion of the guard member comprises anattachment feature configured to be detachably mounted to the guidepost.
 9. The device of claim 5, wherein the reaming surface comprises aplurality of reaming elements, each reaming element sharing an edge withanother reaming element.
 10. The device of claim 5, wherein the reamingsurface comprises a plurality of reaming elements, each reaming elementcomprising a curved reaming surface.
 11. A device for removing bone froma glenoid of a subject, the device comprising: a frame adapted to bemanipulated by a user; a reaming head comprising a reaming surface; acannulated drive shaft rotatably supported by and extending at leastpartially through the frame, the drive shaft rotatable about a driveshaft axis extending through a distal end of the cannulated drive shaft;a bearing supported by the frame and configured to provide a firstconfiguration and a second configuration, the distal end of thecannulated drive shaft being positioned distal of the bearing, whereinin the first configuration, the reaming head is configured to rotateabout a first reaming axis having a first orientation relative to thedrive shaft axis; and wherein in the second configuration, the reaminghead is configured to rotate about a second reaming axis having a secondorientation relative to the drive shaft axis, the second orientationbeing different from the first orientation.
 12. The device of claim 11,wherein the cannulated drive shaft has a distal opening located adjacentto a distal-most portion of the reaming surface.
 13. The device of claim11, wherein the cannulated drive shaft has a distal opening locateddistal of a distal-most portion of the reaming surface.
 14. The deviceof claim 11, wherein the cannulated drive shaft has a distal openinglocated distal of an axis of angulation of reaming head.
 15. The deviceof claim 11, wherein the reaming axis and the drive shaft axis intersectwithin the reaming head when a non-zero angle is provided between thereaming axis and the drive shaft axis.
 16. The device of claim 11,wherein the cannulated drive shaft is straight in the firstconfiguration and the second configuration.
 17. The device of claim 11,wherein the distal end of the cannulated draft shaft is coupled with thereaming head.
 18. The device of claim 11, further comprising a pivotcoupling disposed laterally between the reaming head and the distal endof the cannulated drive shaft.
 19. A kit comprising: the device of claim11; and a guide pin having a first end configured to be disposed in boneand a second end configured to be received within the cannulated driveshaft.
 20. A device for removing bone from a glenoid of a subject, thedevice comprising: a frame adapted to be manipulated by a user; areaming head comprising a reaming surface; a drive shaft rotatablysupported by and extending through the frame, the drive shaft rotatableabout a drive shaft axis; and a bearing supported by the frame, thebearing capable of providing a rotational axis of the reaming head, adistal end of the drive shaft being positioned distal of the bearing;wherein the reaming head is rotated about the rotational axis uponrotation of the drive shaft relative to the frame and about the driveshaft axis when the device is operated to remove bone from the glenoid;and wherein when a non-zero angle is defined between the rotational axisand the drive shaft axis, an intersection of the rotational axis and thedrive shaft axis is disposed within the reaming head.
 21. The device ofclaim 20, wherein the drive shaft is straight when the non-zero angle isdefined between the rotational axis and the drive shaft axis.
 22. Thedevice of claim 20, further comprising a pivot coupling disposedlaterally between the reaming head and the distal end of the driveshaft.
 23. The device of claim 20, wherein, in operation, the device isconfigured such that when the drive shaft rotates the reaming head, thereaming head engages the bone asymmetrically relative to an axisextending longitudinally through the distal end of the drive shaft toream the bone asymmetrically relative to the axis.
 24. The device ofclaim 20, wherein the distal end of the cannulated draft shaft iscoupled with the reaming head.